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BEST AVAILABLE COP.

' G. ALFANl ET AL SELECTOR FOR AUTOMATIC TELEPHONE EXCHANGES March 15 1927.

Filed March 31. 1922 4Sheets-Sheet1 Inventor-J: Guido AZfan( q Leandra Ma B l y g After-r1;

March 15 1927.

BEST AVAILABLE COPv G. ALFANI ET AL SELECTOR FOR AUTOMATIC TELEPHONE EXCHANGES H lHlll \l \HHI ll lllllll llllllllll I |||1| Filed March 31, 1:92 4 Sheets-Sheet 2 Guido AZf'a'm' a andra M3)3&

BEST AVAILABLE COP\ March 15 192 1620620 7 G. ALFANI ET AL SELECTOR FOR AUTOMATIC TELEPHONE EXCHANGES Filed March 31. 1922 4 Sheets-$heet 5 At orney BEST AVAILABLE COP March 15 1927'.

G. ALFANI ET AL SELECTOR F OR AUTOMATIC TELEPHONE EXCHANGES Filed March 31, 1922 4 Sheets-Sheet 4 .[7 ve7z Zora: Guido AZfam Leandra Ma a Attorney BEST AVAlLABLE COP.

Patented Mar. 15, 1927.

UNITED STATES GUIDO ALFANI, OE IIRENZE, LEANDRO MAZZA, 0F GENOA, ITALY.

SELECTOR FOR AUTOMATIC TELEPHONE EXCHANGES.

Application filed March 31, 1922, Serial No. 548,389, and in Italy April 1, 1921.

The present invention refers to improvements in and relates to automatic switch board systems or selectors for electric circuits and particularly for telephone circuits such, for example, as those employed in automatic telephone exchanges in similar installations and its principal object is to provide these selectors (which are adapted particularly for use either as group-selectors or connectors) of compact and simple construction, of sure working and low cost of estab lishment.

Each selector consists essentially, as in systems hitherto known, of three parts, that is to say, a certain number of fixed contacts which form the so-called bank ofjcontacts, these fixed contacts corresponding generally to 100 lines connected to the telephone exchange and sometimes to a larger or smaller number; and one or more movable contacts mounted upon a mechanism which maybe termed the movable equipment, the said contacts being connected, independently of the operation proper of the selector, to the line of the calling station; and finally the motor elements.

It should be pointed out principleof multiple utilization is applied with a law of simultaneous action to the bank of contacts, while it is applied with a law of successive'action to the movable equipment and above all to the motor elements which control it. To this end the contacts in the bank are so formed as to effect simultaneously the connection between the contacts and the bank of one and the same selector, and to'serve for the multiplication between the corresponding contacts of the banks of several selectors. On the other hand, all the movements of the movable equipment, by varying successively the functions performed respectively by the elements composing it, are controlled by a slngle motor, which by means of suitable mechanism acts in a different manner upon the movable equipment according to the various phases of operation in which the selector happens to be.

According to the present invention the fixed contacts are in the form of fiat bars or the like,'and the bank of contacts is so formed that the individual contacts of each series are arranged parallel one to the other, in the same plane, which plane is parallel to other planes in which are arrangedanalohere that the gously and homologously the individual contacts of the other series. These fiat bars extend uninterruptedly beyond the bank element to which they belong, so as to constitute a series of banks of contacts, each constituting a complete unit, that is to say, a multiple bank of contacts serving a number of selectors, without the use of multiplying cables.

The foregoing is a very important characteristic of the present system of selectors, upon which depends its great simplicity and certainty of operation as compared with other systems of selectors hitherto known. In these systems the banks of contacts are formed in metallic blocks arranged radially in a certain number of planes between semicircular sectors of insulating material. The group of sectors and contacts is bolted together so as to form a block and the contacts extend into the interior of the block to form the fixed contacts proper and extend externally for the attachment of the wires of the multiplying cables which in this case are necessary.

According to the present invention the movable equipment-controlled by the action of one electromotor having interrupted or step by step movement, (or one having continuous movement),causes the movable contacts to move, and they establish the desired connection with the fixed contacts of the bank, moving first in one direction to pick out one of the several series of fixed contacts and then in another direction to pick out the individual contact in the series. These movable contacts are mounted so as to movesuccessively in two directions at right angles to one another. In some simplified constructions, however, and in particular in those constructions of selector in which the fixed contacts are limited in number, the movable contacts are adapted to move in one direction only.

The principle of multiple utilization surcessively is applied by means of a special device which may be termed an electronicchanical combiner and not only provides in known manner for successively changing the internal circuits of the selector necessary for controlling it during the different phases 0t its operation, but it also accomplishes in a manner absolutely novel various operations which are entirely mechanical. They may, for example consist in modifying the meezaaze chanical connections existing between the diflerent elements, so rthat the movable equipment may cause the contacts to move successively in two directions, although there is only one electromagnet motor- ,01 in effecting the release of the movable equipment so that it may return to ,the pointlof departure; or in other analogous operations such as connecting the armature of the electromagnet motor with the shaft for rotating the combiner so :as :to move it, without an additional motor sbeingrcquired. from one posi- :fiion to another .-accrding to the phase of operation of the selector.

dVllat has beensai-d' above represents an- .other of the characteristics .which makes the :apresent system. of selectors essentially difuferent from selectors 'xhithertoknown and increases the already great simplicity and certainty-0f its operation, idueito the above described special form .of unultiple bank. It mute seen that this arrangement a single electromagnet takeszithezplace of EEOHIY- or .--1ive. relectromagnets, :that is to say, the elecntromagnetmotor, provides in thegcase (direct- 1y lorwindirectly fOIntllB Etwowmoivements of Ethe movable equipment, )fOI sits iI'GlGfi-SG, and

rit may also provide ifor'the'control :of the .combinerywhereasiin othersystems two sepa- .-rate electromagnets are lprovided for the movements of the movable equipment, a

ithi-rd ielectrornagnet for, its release, a ;fourth for the control of thewdevice zwhich -,corr.esponds to the =present.-comhiner;and ffinally. a

fifth ele-ctromagnet for effecting the disconnection required when the said device returns to z'the position of restwhy a return 'lnovement.

In the accompanying drawings Fig. 1 shows a perspective VBlW 0f a-multiple bank ;of :fixed contacts with corresponding movable-contacts, and Fig. 2 isa transverse section on a smaller scale of two modifications; 8 is fin-assembled viewlof =a 'selectorwith =t\v-.o movements, and'iFigs. 4 to :8 illustrate special constructions and corresponding --modifications; Fig. '9 shows a selector with one movement, and Fig. 10 a modification thereof. 11in Fig.1- there =is shownat the upper part (which ison'ly the upper part inthe draw- --ing-) a :portion of a multiple bank comprising, atthe right hand side. the head of the bank the same term maybe applied'to the other end also), at:the centre two complete bank elements relating to --t\vo commutators and att-heleft-hand side a portion ofa third ban'k element.

'Ehe multiple bank illustrated serves for two-pole lines (it :will beevident that in this ease -the commutators served thereby are also two pole") with separate groups for each 'pole, that is to say, there. are :two groups, leach ofavhich by itselzfanay constitute a onepole bank. IIn-the first group-are assembled BEST AVAILABLE GDP.

all the contacts a which may be the outward contacts-and -in-the-second;grou,p are assembled all=the contacts J) Whichunaybe the return contacts. Each line is therefore made up, in the .Qase o,f a two-pole bank, .of a contact a and a contact 7) and in particular, therecorrespond.toeach line 1, 2, w, the cont-acts an 6 a b a b All these contacts as has been-statedand as can be seen from the drawing, are in the form of flat .bar-s, abut may-aloe of. any other suitable shape.

For'the sakeiofsimplicity in :the drawing *the bank of contacts is shown corresponding only to '25 rtwoapole lines, divided into live series, each of five lines, oarnyiing infill-'50 contacts \in ithe form of-fiat :hars. All these Ibars are parallel :to {one :another and .are. fill- -ranged at equal distances from .oneranother,

iinya-rnumber.of'planes. The bars offthe same series .of linesare arranged in tmoiof'ithese planes,one plaueilnreach group, of -.the bank for example, the individual bars-gamf zthe first series (lines-1; 12,113., 11116 :5).,-\th is :to. say: the 3 78 a, each t, :and a ets .ar-

. iranged Eat equal-distances ifrom one another in the first iplane lILaGfi-Qh group; \While all the individualharsbl, :5 .6 '6 and J2 of the-same first series are-arranged;at the same distance. from :one anotheriin the first plane iin the other groupgand analogously arearranged the ether bars .a and 1b of the @other rfour series of :lines.

All ,the five planes of harsa, intone group are parallel to and equidistant from one aniother-andiareiusually placed at theisame (listance from one another as the sever-5, 1 bars in each plane; and analogously {the five planes of bars b iin ;the-oth er;group are :parallel to .one another and equiwdistant, and the loars in rtllOSB planes are at equal distances apart; the distance -.bet\veen;'the last plane a and the first plane I) may, ,however, be different, as may be found convenient. -Moreo.ver allithe bars a and .Z) belonging to lines of the same order in each series, for 1 example, the harsaf, at, a 0 and (1 Z9 I), I), b fland Z), and so on, are arranged in planes perpendicular to the planes of the series of lines.

In order that the fixed contacts in the form of ifiattenedhars may rigidly retain their respective positions and be effectively insulated from one another, :they are lined in supporting plates 26. 26, 26 etc. of suitable form and. composition, arranged ,at ,regular yond the plate 26" can be seen the third bank element. Fhe number of bank elements WlllCll go to form a multiple bank depends upon the space available 'upon the frame change has to provide;

-- Be ow thefirst tworbank elements is clearly seen part of the movable equlpment of the -first two commutators, that 'is'to 'say, the switch contacts 27 with "their mounting.

Each contact is formed of two similar springs-28, one opposite the other but electrically connected. At their lowerends the 'said springs are fixed in blocks 29 rigid with the switch contact carrier 30 which isparti'ally visible. The'"springs'are sitliated in planes parallel to the planes of the bars in 20 .gage 5 the said bus perpendicularly or at a the'ibankof contacts and so fixedas'to ensui'table'angle-of incidence 'and to embrace them and to press against their side surfaces.

At the upper ends the springs are shaped wso asto wipe'or r-ub easily' 'upon*the: side surfaces'bf the bars and to ensure a good electric fcontact'with them; moreover"the rubbing extremities should the shaped so as to pass from one bar to the ne rt without causing'a' short circuit between the bars.

- The'springs aie"'covered by suitable sheaths 'ofins'ulating material 31, covering them on the inside and outside fr their whole length,

'except'for'the rubbing ektremities. so as to "prevent, undesired contact between the said springs and any one of the bars over which the rubbing extremities havepassed. In view of the parallelopiped'form of the multiple bank it is clear that the movement 'suited'to allow the contact brushes to select first of all the series of lines and then the individual line in that series, is as already indicated, namely rectilinear movement in a plane at right angles to the bars'in the bank. Moreover as clearly shown 'bv the'drawing which indicates the switch contacts of the first and second selectors respectively -in the position of'engagement with line'3 and in the position of rest, the said movement is first of all perpendicular to the planes of the bars and in a direction towards 'the right hand and then perpendicular to the said bars inan upward direction.

'lhe'bank of contacts with one-pole groups as described above with brush contacts is the most simple and generallyemnloyed form, because it lends itself readily without any change to the case of commutators having any number of oles. By arranging one beside another, two, three. four or more one-' BEST AVAILABLE COP. :3

vided into two onepolc groups but the planes of contact barsmay be arranged in a single two' pole group. To this end it is sufficient to follow the plane of individual bars a of one series (for example that of the bars a a, a a, and a ,-with' the plane "of individual bars- 6 of the same series (for examplebars 6 I), 12 b. and b). This arrangement may be carried out in two ways, either by'c'ou'pling the'two planes (1 and 'b' of the same series or by coupling the planes 6 of one series 'with the planes (1. of the succeedqng series.

' i Fig.- 2 shows in transverse section and on a'reduced scale a four-pole bank (again with '25 lines for the sake of simplicity) divided into twotwo-pole groups; In the 'first two- 'vpole'gr'oup 'the'planes of bars are arranged according to the first method and in the other group they are arranged according to are suitably modified, as are also the insulating sheaths that surround them. It is evi dent that the multi-polar banks, instead of "being formed of several one-pole groups corresponding to the number of poles, may also be obtained by uniting several two-pole groups such as those above described with the addition in some cases of a single onepole group; *It' is moreover clear that in the 'case'of banks formed by a single series of lines (such as will be used with the simplest 'form of commutator) the division of the 'bank intoone-pole "groups has almost iden- -tically"the same 'result as the division into two-pole groups.

'Figure 3 shows an assembled view of a commutator with two movements, compris- "ing a bank of fixed contacts, a movable equipment, motor elements and an electromechanical"combiner. The said combiner, upon which depends particularly the operation of the whole apparatus, can be seen at the left of the figure; and it comprises (see also'Fig. 6) a shaft 34, carrying a certain number of discs 35, 36, 37. 3 etc. the edges which are provided with a cam profile'which may be disposed either radiall (as in the figures) or axially in the direction of the shaft, that. is to say on a crown mounted on the edge of said discs. 1 It'should be pointed out that in place of a simple profile it is possible to =employ .in every case-a ohannel-or=slot. il heilevers 39, 40, 41 etc. of suitable kind and shape are caused by suitable means to slide :with one of their ends upon the profile of the discs and are moved by these profiles and may assume two, three or more 'difierent positions and :control consequently by :means of the other ends the draw irods 42, 43, 44: etc. carried and guided by suitable-supports 45, fixed to the frame 46 of the commutator. These-controlled movements are then transmitted by the draw rods to the several mechanisms which compose the movable equipment and the motor elements and modify their connection with one another. .iome of these said mechanisms may 'be-con trolled (through the said draw EIOClS and in particular the draw and 42) by the changeover electromagnet 47. or rather :by rits armature 48, every time that it is necessary to change over from the movement of'the movable equipment to the movement of the combiner. The change-over electromagnet 't'ormsan integral part of thesaid combiner.

The use of a special device, such :as the said combiner :to produce the-sue essive me chanical changes described accor ing to the necessities of the various phases of operation 'is particularly adapted to automatic telephone exchanges.

In addition to the said purely mechanical operations, the combiner provides in known manner for=analogous successive ohangesiof an electric nature. In the figure itiwill be I towardsithe :left'jn -..\the::direct1on of their seen that corresponding to the position-of the disc 38. thespring contact 49 1s pressed by the profile of the disc into three-definite, positions,-either against the fixed contact 49' so as to close one-circuit, or against :the

cuit, or finally in the :midwaywposition-between the two-contacts so that both circuits remain open, as shown in :the drawing. Similar spring contacts, :rthat is to say, the

end contacts 50yand the lateral contacts -51 may be operated in 'known manner by the movable equipment on starting its :first and second movements respectively.

The shaft 34 of the combiner turns in a counter clockwise direction when viewed from its lower extremity and with it turn the discs, the whole being rotated by the ratchet wheel which is controlled by a pawl 84. The shaft and consequently the whole of the-combiner can-only come tor-est in definite positions which are conveniently fixed at the same angular-distance from one another.

In each of the said positions the combiner accomplishes according to the-profiles of the discs a certain number of mechanical connections and a certain number of openings and closings of electric circuits; it may moreover perform analogous operations in 1, 2 2 BEST AVAILABLE coPi the intermediate position :of'transit, that is to :say, in the positions :through which the combiner passes, without stopping, during the rotation of the sharft. The order in whieh'these operations follow will clearly-be invariable and predetermined.

The number-of the positions of the combiner, the number of the discs-and their sprofile, and also the kind and shape of -levers employed may vary, according to the electromechanical combinations that are re- -qu'ired for each particular model of commutator, to the particular use to which it is -to be .put :and to the particular internal circuits. In the figures under consideration however, theconibiner has six possible :posi- 'tions.

[In the upper :part of Figure .3 is seen the bank of contacts in section on a plane perrpendicular to the bars, so that tone :of the plates 26 in which thezbars are fixed :isseen. The plates and *by-their means the vbank -of contacts are suitably mounted on the .frame 46.

- planes' of bars :an'd theydie in'la iplane at right angles to the bars. They are held-and guided by special supports imoun'ted upon the frame so :that they can move freely axis and return to the Z-startinggpoint, their return movement tbeing :ltimited by 'the flanges or collars-i543, sand :56. The said shafts cannot, however, turn about their fixed contact 49 'so as to close another c1I- 8285. L 1 The double-translatory moivementof the :brush carriage -and,--.-cons'equently of the switch'zcontacts @is -produced by a. single movement of-ithe controlliagishaft which is effectedain two phases. In theifirst phase. the- -controlled' shaft is -lockctl {to the controlling shaft and-:b'oth :motle together; and in :the second plume-ion the other hand the contihe controlling shaitimotfes. The arrangement is such rt-hat the-controlled shaft is at all times locked to one or tthjeother and is never independent. Ilh-isaesult isefiectetl by means of the combiner which controls suit- .-able engagingqmeanst b e mslato y-[movemen s a the' a'se sun l trolled-shaftis locked to f'the theme and :on'ly consideration there are 10 teeth. The controlled shaft, on the other hand, has near its corresponding end (at the left in the figure) slots 59 which are also arranged at a distance from one another corresponding to the teeth of the racks 58, but are fewer in number and in fact equal in number the series of lines, in the present case, five. The said controlled shaft carries, moreover, on this end a sleeve 60 which can turn about the shaft but which cannot slide along the shaft.

The engagement mechanism just mentioned consists essentially of this sleeve and of the elements working with it or of similar devices'taking their origin from it. Upon the sleeve are mounted at right angles to the shaft two arms (compare the details in Fig. 4) the first of which 61 is-formed like a blade and can enter the slot 57 in the controlling shaft thus locking it firmly to the controlled shaft; whilst the other arm 62 is in the form of a fork. This fork engages a rod 63 which is-fixed parallel to the controlled shaft upon a lateral extension 64 of the draw rod-M; and this rod is of such length-that it always remains engaged by the fork even when the controlled shaft travels its full course.

The draw rod 44 enters-with its end 65, which is suitably shaped, the slots 59 so as to lock the controlled shaft to the frame whenever the lever 41 acts by means of the pin 66 upon the draw rod 44. When this action ceases the draw rod returns to its ordinary position and releases the controlled shaft which is drawn back by a suitable opposing force. It is evident that in view of the relations between the rod 63 and the fork 62, this return can only take place when the blade 61 registers with the slot 57 and can freely enter it. There is thus realized the condition that the controlled shaft is always looked either to the controlling shaft or to the frame of the commutator; it must be pointed out moreover that the connection with the controlling shaft can only take place when the two shafts are in a particular position with respect to one another, whilst. the other connection can take place in as many positions as there are slots 59.

The switch contact carriage 30 is mounted upon the controlled shaft and it is guided by a guide frame 67 which is carried by the controlled shaft or by similar means so that the carriage possesses independently of the controlled shaft a single freedom of movement perpendicular to the two shafts and at the same time perpendicular to the contact bars.

This independent moven'ient of the carriage is produced. by the movement of the controlling shaft during the second phase, that is to say, by its movement relatively to the controlled shaft, which during the sec- BEST AVAILABLE COPv 6 ond phase remains stationary; it is as has been said perpendicular to the movement effected by the brush carriage with the con-' trolled shaft and the controlling shaft during the first phase, and may be obtained by various means which generally speaking are based upon the means to be described below. A pinion ($8 of suitable length has its axis journalled at 69, in the frame 67 parallel to the contact bars. The '-pinion engages with two racks 70 and 71 perpendicular to one another and parallel respectivcly'to the two movements of the switch contact carrange.- in parallelplanes, thefirst ofthenrnpon the controlling shaft and-the other uponthe carriage. It is now clear-that when'the con-' trolling shaft takes the controlled shaft in its movement towards the left, the carriage" follows the said movement withoutmaking any movement of its own and moves theswitch contacts to the point for selecting the series of lines required;-while when onl thecontrolling shaft moves to the left .an the controlled shaft is stationary, the rack 70. causes the pinion to turn in a-elockwise direction and the pinion in turn by means of the rack 71 causes the carriage-to rise, so that the switch contacts establish contact with the individual line in the series chosen. Finally the lower part of Fig. '3 shows The said racks are fixed as is natural the motor elements, that is to 'sa'y'the step magnet 72 -with -its armature '73 andthe various mechanisms which receivetheir movements from it. It should .be here noted that the successive utilization which has been mentioned of a singleelectromagnet'for giving the necessary movements to the'elements composing the movable equipment and also for moving the combiner, can be done with the aid of the combiner, substantially in two ways; either by bringing the several mechanisms which are to be moved or instead of bringing the mechanisms, bringing special elements connected therewith successively into engagement with the step magnet armature; or by bringing the. said armature or rather a movable elementconnected therewith successively into engagement with the said mechanisms. The first way most satisfactorily meets the operative requirements because it makes possible, while confining each instant the movement to the individual parts necessary, for the employment of a simple armature, that .is to say one without movable.connections or. otherv accessories and itis consequently better adapted with an electromagnet of equal power to answer to rapid impulses.

In accordance with the first way the end 73 of the step magnet armature is suitably shaped and transmits directly its movement to the rods 74 and 75, which in turn are put into engagement with it by the draw rod 49., which moves them by means of the pins 76and 77,. Theatwotrods 74:; and 75. are. pivoted. at 7,8 and 79 respectively upon supports 80, and; 81 which. tunn about pivots.- 82 and 83. They' transmit the movement received,

ifrom the armature 73, respectively to theratchet wheel 52 and consequently to the shaft of-the combiner, to. the rack 58, and seq nt y to the n ro l g h it. y ans. of pawl nd he dnaod: 42 isoperated so as to present the rod 7 k and onsequ n y to ake. ea y.- r. he movement of the combinen, either-by: means. of the lever 39 (as; shown; in the. drawing) T- y' hfi; hange r magnet ehe a hamdfilis ctuat d o. s o. P es h mod. 5; and-conseq ntly. Q-ma e ready or hawr ment o e c tr lin ha y. m an Q ny ui le.- pp s ng. force,- which can. act, it will, be understood-,

when p neithe the lever 38. nor the, anmatnre.

48 is acting.

A1 reta n g 9 M586. piv te at; l s the controlling ,sha ft by means of the racks. 58 n he. uca iv po it ans aa hei. h

; said pawl is caused, by the. drayv rod; 43 to dis ngage t l om. e rack. (as ho n. n? dra ingh; and i s nih i the an caused, to engageinthemaek by meansof a tab eracing r e.

hcs ing', h w r o; e con y of transmitting the movement (see Fignre 5) the. armature. 73 controls the rods ,7 4: and, 7.5 by means. offa finger 88 pivotedat 89 upon the said, armature. which finger controls. in

turn that one of the two rodstowhich it is presented by the. draw rod. 42 of the combiner bet veenthe. pins/7,6 and 77 of which it carried; The. draw rod,42 a,cts in. this case upon the. finger 88.instead o f upon the, rods 741and It is easy. to follow. the. operation of the commutator, in asimple example,.in one Of the caseswhere. it is most frequently used, in the; case. that istosay Wherelit performs. the operation of a selector in an automatic telephone exchange.

When the commutator, enters. into operation, the step magnet receivesa current i111.- pulse and attracts the armature which by means oft-he rod 74: and corresponding pawl. causes the combiner to move from position I to position II. Inthisposition the levers 39 and release their corresponding dra v rods; and the rod 75. is brought into engagement with the armature 7,3 whereby the pawl, 86,engages with the rack 58. Current im; pulses from the calling stat-ionthen arrive, directly or retransmitted. by. relays, to the. step magnet which attractsits armature as. often as; it. receives these impulsesand since the. armature operates. the rod 75 and its vcorresponding pawl, the controlling shaftand; with it. all the movable, equipment moves. towards the left a corresponding number of steps. If the callingstation aswemay snp-.

BEST AVAlLABLE COP pose. has. sentonly a single impulse, the cone trolling-shaft movesa single step, remainingheldin thisposition by the paml;86 and| theswitch contacts are moved into a position:

opposite, thebarsof the first series. 013 lines,

Immediately afterwards by the combined action. of. thehead contacts as openatod; by the; firstmovement of the movable equipment. of; the cessation of, impulses. from. the calling station, and of various relays which are-not indicated in: the drawing andthe operation, of which does not concern the present speci fication, the changegover magnet 47 is ex cited; andattracts ts anmature so as toagaiin make thestep magnet ready to operate the con' hinerand, this takes place immediately a new current impulse. reaches the said: step: agaat. 11 mm n: e p s i n. III; of he iner e haled/ is cr n giz d. t iallow h las r 75. to returnto a; positionopposiethe a rma I fl-Bihe dnaw c k bpre dhy he las r 41 enters with its" end, into-the.- slot 59. hich ppqsi ait ni ep fi nt ca e h r t Q th) n. 1-. tthesame-. im aus s he blade, 61, to leave the; slot 57. Since, the qnt q ledh ftis hu c ed to h rame- 46'; and on y. he ntm lingi t fr e o move, the second current, impulses from the; calling, station are transtormed into; a further displacementof, the,controlling shaft to vards the left and consequently into, a, vertical upwarddisplacement of the canriage; and s\vitch,contacts, It, fnr example threeew mpulses: r v remmh c ling; stati nhccon rpll ng-zshatt mo e hr e m s ep comingi m fist e .ha ng;mo e i nn eps in; all, and theswitdr-contacis are moved so. as to establish: contact Withline 3, as indi-.

catedinEig. 1', that is. to say \viththe bars 1 a and. 5. The whole movableequipment; then remains inthis position held. by the pawl 86. Immediately. afterwards, and again by the combined action above: de-

scribed, to which may be added in this case the commutation of the latcralcon-iacts 51 caused by, the firstindcpendent movement of the carriage the change-over magnet 47. is againnencited and the step magnet is again prepared to operate the combiner and immediately a new current impulse reaches the step magnet, the. combiner etc., passes to position IV inwhich the lever 39brings the draw rod 42again into-the position shown in the figure.

The; position under consideration and-thefollowingpositions, IV, V and VI may. serve for other necessary operat ons such for example as testing the stationcalled, the, transmission of the signal busy to the calling station, it thestation called is busy, the transmission of the calling signal to the stationcalled if it is.free, the operation of the meter and: finally the conversation. these operations are carried out inclepend- All;

When the conversation-1s ended which we may suppose takes place when the combiner is in position'VI, the current impulse traversing the step magnet brings back the combiner into the position of rest, thatis to say, into position I, in which the draw rod 43 causes the retaining pawl 86 to disengage from the rack 58. In this manner the controlling shaftunder the action of .a suitable opposing force travels back until its collar 55 strikes'against the blade 61, and at the same time-the brush carriage under similar action sinks again uponthecontrolled shaft; it is onlyat this moment, since in the position I of the combiner the action oftheflever 4:1 upon the draw rod 44 ceases,-that the blade 61 can (enter thehslot 57 ;opposite which it finds itself and thereturn movement of the controlling shaft can .continue, taking with it the controlled shaft .'until they have both regained: their starting position, that is. to say, until= the flange or collar '56 .strikes against the frame.- g j,

The second. movement of the :brush :car-

riage, that is'to say the independent.move-- ment may be obtained as has been said in a variety of Ways other than that above described. In particular there may -be employed instead .of the pinion'68 simultaneously en aging with the two racks and 71, two toothed wheels or two' toothed sectors, fixed upon the same axis 69, each engaging with one of the racks. It should be noted that if the wheels or the sectors are of different diameters the advance movements made by the controlling shaft will be different from those made by the carriage.

Finally there may be used instead of wheels and sectors, alever bent at right angles, pivoted about the axis 69. The two racks 70 and 71 are replaced by. two .pivot pins arranged so that when only the controlling shaft moves the first-pivot which is fixed to the said controlling shaft pushes one arm of the bent lever while the second pivot fixed to the brush carriage is moved by the other arm of the lever so that the carriage with the second pivot is moved vertically. It should also be noted that if the arms of the lever are-unequal the movements of the control ling shaft and of the carriage will be of clifferent extent.

It is also possible to use, instead of a bent lever, eccentrics or an inclined plane mounted upon the controlling shaft or upon the carriage, or to employ suitable combinations of the elements mentioned or any other suitable element. Finally it is also possible to ar-' range the two shafts, both the controlling and the controlled shaft, in a plane parallel to the contact bars instead of in a plane perpendicular to the said bars, or even in another plane, or one of the shafts may be made hollow and the other shaft arranged within it.

In the principal construction of the movable equipment which we havedescribed and in its modifications, the contact brushes are always moved by a double translatory movement. e have even noted that the said 'movement is that which is most suitable,

given the characteristic form of the bank of contacts. This assumption being made it may be pointed out that the second movement in particular of theswitch contacts, the movement for the selection of the individual line in the series may, while retaining sufficient simplicity in the elementsfbe a rotary movement. In this case the whole of the movable equipment takes a form analogous to that of other systems'of selectors already known.

Figure 6 represents in a't'ransverse section of the bank of contacts, the assembly of a commutator having two movements, pro- .vided with a movable equipment with rotating switchcontacts orbrushes. The combiner and the bank of contacts can be seen respectively at the top on the left hand side and at the right, and the movable equipment is in the centre of the figure. The movable equipment comprises simply the shaft 90, on which are directly mounted by means of pincers 29 the contact brushes 27. The shaft is arranged perpendicular" to the planes of the contact bars beingjheld and guided by special supports mounted on the frame 46, so that it is free to travel easily towards the left in the direction of its axis and to return to the starting point, its return movement being limited by the flange or collar 91, and also being free to turn in both directions.

The contact brushes are formed of springs 28 identical in form and arrangement with those already described except for the fact that as is convenient in this case they meet the first bars (luring their movement at a smaller angle; and this can easily be seen from Fig. 7 which shows a part of the com mutator in longitudinal section.

The double movement of the carriage and the consequent movement of the brushes is here replaced by the double movement first of displacement towards the left and then the rotary movement in clockwise direction, looking at the left hand end of the shaft; and in the first movement as will be seen the brushes are brought to a position to select the series of lines required, whilst in the second they are caused to establish contact with the individual line in the series selected.

In order to receive these two movements 3EST AVAILABLE COP\ '7.v

from the step magnet, the shaft bears on: one of its ends, theleft hand end inthe figure, tworacks 92 and 93-; the first is-provided with-annular ratchet teeth at adistance fromone another equal tothe distance apart=of theplanes of contact bars and'in number equalto the number of series of lines (in the present case five teeth) whilst the other rack is in-the' form of longitudinal grooves-orratcheivteeth in number equal to the number of linesin a series (in the present instance five). Thedistance between the longitudinalteeth gradually increases proportionately with the-angle through which the brnshesmust turn in order to reach the bars. Assuming that the bars are-equal distances apart, the angularmovement of the shaft: increases during the passage ofthe brushes t'romone bar to thenext. Nevertheless if a decreasing distance were chosen between the bars the angular movement of the shaft could remain constant.

At the lower part of the figure are seenthe motor elements of the commutator which are entirely identical with the element's-already described. However, between therods M and 75-there is here a third rod 94: which by, means of a bent lever 95-piv0ted at) 96 and'of the pawl 97, transmits a rotary move- 1nent to the shaft. There is also-asecond retaining pawl 98' pivoted at 99- and controlled by the finger 86"0f thepa-w-l 86 and' consequently by the draw rod 43; which'retains. withthe aid-of the longitudinal rack, the shaft in=the successive positionsav-hieh it reaches in its rotation. However in this case it will be understood the-control rod 42 may act, instead of'upon the rods 74;.7 5' and 94', upona finger ofthestepmagnetarma ture in the same'way' as'wa-s' indicated ins Figure-5.

The operation of the said commutator with with rotating brushes as a-connector is eifectedin the manneralreadysdeserihed' em cept for slight differences. In the position 111 of the combiner, sin-cethedraw ro'd' 42 presents the rod 94- to the step magnetannature, there is obtained-arotary movement of the shaft when the secondcurre-nt' impulses arrive from the callingstat-ion. Finally when the conversation is finished andthecombiner returns to position-l tliedraw rod 4-3 causes the pa-wls- 86-an-d98' to-disen-gagefrom their respective racks and=tlie-shaft, under the action of suita-hleopposing'forces; first of all rotates in the opposite direction until the contact'brushesare free-ottlie-bars and then returns to its position of-rest;

It is important to note how itpossibleto combine the principal construction otthe movable equipment with-tlie equipment of' rotating-brushes descrihedahove. It is in fact possible to give the brushes the doublemovement as in theprincipal construction by makinguse of" a-shat't having-a movement of displacement and a movement of rotation. Figure 8 shows by way of ex ample a method of carrying out this com-- bined construction accordingto which on theshaft 90 there are fixed, instead ofbrushes, two similar projecting fingers- 100" between which. is arranged a pinion-101",.en-- gaging with the rack 102 of the carriage303 The said projecting fingersserve-to set the carriagein movement sliding alonga shaft 103 tii ed to the 'frame 46. This shaft only serves the pur-pose'of guiding: thecarriage, when dhringthemtation of the shaft 9Wit is obliged to move in'an upward direction: The said guiding element can often he ar-' ranged directly betweenthe carriage and the frame or-in any other'equivalent man'- ner. In-the-sameway as has been-above described with regard tothe principalcon struction of the movableequipment, and here also it is possible'to employ instead of the elementsd'escrihed other-kinematic ele-- ments suitablycombined and performing eqniva-lent functions;

Fignre- 9=illiistrated aconstruction of a simplified commutator provided with a single direction of moveinent'. Ahove' it'is seen' the bank-01 contacts which by way of ex-- ample is-formedofa sin'gle'series offitwm pole lines; that'i's-to say,'having'on1y- 1Uc0n-' tacts in the form of fiat bars." Belhvi' isthe movable-equipment comprisihg the shaft *104: and the bruslirarriage' 30'? The shaft' re ceives its motive impulse-through thera'cli" 105-and=transmits=it y means of the other ra'clrifito the*pinion 6HWHicli-in turn transmitiit to 'the' thirdirack 71- so that the carriage is obliged to move" upwards. The shaft' 106 is}- fixed? upon the frame-'- 46'" and Even-inthis siinplifiedfbrm of commutator it' is possible to employan' equipment with rotatingbrushes; (similar'tci-that shown in f Fig. 6) or a combined leqnipment" (similar possible to replace the pinion by of an'v-oftlie arrangements discussed.

Fihally itis possihle to attain" a stillgreater degree of simplicity, (compare Fi 10), hy'reuniting'the shaft'104- and-thie 'carriage" 30 into'a singl'organ; Iii this case the movable equipmenti is reduced to the" carriage alime, which, suitabllfy guided by the. frame 67;, carries directly 'the. rack 107 by'means ofwhich it receives themovement one-pole groups;'a'controlling"shaft m'ou-nt ed in said frame; a controlled shaft mounted in said frame, said shafts being parallel to one another and perpendicular to the planes of the bars and arranged in a same plane perpendicular to the bars; a switch. contact carrier having separate switch elements for each group of the bank mounted in said controlled shaft and adapted to coin tact with said bars; means for actuating both said shafts to move said switch carrier laterally under said bars; and means for actuating said controlling shaft laterally, said controlled shaft remaining stationary for moving said carrier longitudinaly in order that the switch elements may contact with said bars.

2. A selector system for automatic telephone exchanges comprising a frame; insulating supporting plates secured to said frame; a plurality of parallel flat bars arranged transversely to and in said supporting plates to form a succession of banks, said banks being divided into separate onepole groups; a controlling shaft mounted in said frame; a controlled shaft mounted in said frame. said shafts being parallel. to one another and perpendicular to the planes of the bars and arranged in a same plane perpendicular to the bars: a switch contact carrier having separate switch elements for each group of the bank mounted in said controlled shaft and adapted to contact with said bars: a combiner associated with said parallel shafts: an electromagnet for oper ating both said shafts laterally to operate said switch carrier laterally: and means controlled by said, combiner for operating said controlling shaft laterally, said con trolled shaft remaining stationary. to move said carrier longitudinally so that said. switch elements will contact with said bars.

3. A selector system for automatic telephone exchanges comprising a frame having a plurality of flat parallel bars mounted therein by means of insulating supporting plates; actuating means mounted in said frame; a switch contact carrier having switch elements mounted in said actuating means; a combiner comprising a shaft and a plurality of discs; a plurality of levers associated with said discs; and means for rotating said shaft and discs to actuate said. actuating means in order that said switch elements may contact with said bars.

4:. A selector system for automatic telephone exchanges comprising a frame; insulating supporting plates secured to said frame: a plurality of parallel flat bars arranged transversely to and in said support ing plates to form a succession of banks, said banks being divided into separate one-pole groups; a controlling shaft mounted in said frame; a controlled shaft mounted in said frame, said shafts being parallel to one an other and perpendicular to the planes of the BEST AVAILABLE Com,

bars and arranged in a same plane perpendicular to the bars; a switch contact carrier having separate switch elements for each group of the bank mounted in said conrolled shaft and adapted to contact with said bars; means for actuating both said shafts to move said switch carrier laterally under said bars; a pinion mounted on said controlled shaft and adapted to engage the controlling shaft laterally, said controlled shaft remaining stationary to move said carrier longitudinally by means of said pinion in order that the switch elements may en gage said bars.

5. A selector system for automatic telephone exchanges comprising a frame; insulating supporting plates secured to said frame: a plurality of flat parallel bars arranged transversely to and in said. supporting plates; a controlled shaft mounted in said frame; a controlling shaft mounted in said frame having ratchetteeth at one end; means for connecting said shafts together; a combiner comprising a shaft and a plurality of discs; a plurality of levers associated with said discs; a switch contact carrier having switch elements mounted on said controlled shaft: means associated with said ratchet teeth for moving said shafts laterally to move said switch carrier laterally; and means associated with said ratchet teeth for moving said controlling shaft laterally to move said switch carrier longitudinally so that said switch elements may contact with said bars.

6. A selector system for automatic telephone exchanges comprising a frame; insulating supporting plates secured to said frame: a plurality of parallel flat bars arranged transversely to and in said supporting plates to form a succession of banks, said banks being divided into separate one-pole groups; a switch contact carrier having switch elements thereon for each group of the bank and adapted to contact with said bars; a pair of parallel shafts mounted in said frame, said switch carrier being mounted in one of said shafts: a combiner associated with said shafts: means for connecting said shafts and said combiner together; means for operating both said shafts to move said switch carrier laterally under said bars; and means for moving said carrier longitudinally, one of said shafts remaining stationary so that the switch elements may con tact with said bars.

7 A selector system for automatic telephone exchanges comprising a frame; insulating supporting plates secured to said frame; a plurality of flat parallel bars mounted in said supporting plates; a combiner associated with said frame comprising a plurality of discs; controlled. and controlling shafts mounted in said frame; a plurality of levers operated by said discs; a step magnet for operating said combiner and AiiAMaBLE cos:

said controlling shaft; a change-over magnet for controlling the actuation of said combiner and said controlling shaft; means for moving said shafts simultaneously upon actuation of said step magnet to move said switch carrier laterally under said bars; and means for moving said switch carrier longitudinally in order that the contact elements may contact with said bars.

In testimony whereof we aflix our signal0 tures.

GUIDO ALFANI. LEANDRO MAZZA. 

